(1) Field of the Invention
The present invention relates to an interface apparatus for transporting substrates between substrate processing apparatus that successively carry out processing, including photoresist application, exposure, development and etching, of various types of substrates such as semiconductor wafers and glass substrates for liquid crystal displays.
(2) Description of the Related Art
Several types of processing apparatus are arranged serially to form a required processing line. These apparatus include an application processing apparatus for applying photoresist to the substrates, an exposure apparatus for exposing the substrates with the photoresist applied thereto, and a developing apparatus for developing the exposed substrates.
Each of these processing apparatus includes a single processing unit or a plurality of processing units. The application processing unit, for example, includes a contact promoting unit for causing vapor of a resist contact promoting agent to contact substrate surfaces, a rotary coating unit, a heating unit, and a cooling unit for reducing substrate temperature to room temperature. Each processing apparatus also includes a substrate transport mechanism having a movable arm for carrying the substrates, with the various processing units arranged around the transport mechanism.
The substrates are transported from one processing apparatus to another by an interface apparatus disposed therebetween. In this transportation, the substrates are once transferred from the substrate transport mechanism of one processing apparatus to the interface apparatus. Subsequently, the substrate transport mechanism of the next processing apparatus receives the substrates from the interface apparatus.
The known system as constructed above has the following disadvantage.
When the processing apparatus that receives the substrates (hereinafter referred to as a downstream apparatus) becomes inoperable owing to some trouble, the interface apparatus cannot dispose of the substrates. Consequently, the processing apparatus that gives the substrates (hereinafter referred to as an upstream apparatus) must also stop operating. All the processing must be suspended until the trouble is eliminated, which results in a low operating efficiency of the processing apparatus.